What was found
FLT#324, LAX-JFK. (ETOPS) . WITH LEFT TANK PUMPS OFF, APU RUNNING, FUEL LO PR MSG ON APU SYSTEM PAGE ( APU FUEL PUMP ). REPLACED APU FUEL PUMP (4QC) IAW AMM 28-22-51 OPS & LEAK CHECKS GOOD ETOPS GROUND VERIFICATION ACCOMPLISHED MX4 UPDATED PLACARD REMOVED.